Air ionization and cleaning arrangement

ABSTRACT

An arrangement by which the air within an enclosure is ionized and cleansed. A high voltage source applies a DC potential across two electrodes in which one electrode is suspended from the ceiling, whereas the other electrode is supported by the floor of the enclosure. Radioactive substance is embedded within electrically insulating supporting members secured to the ceiling electrode. The radioactive substance ionizes the air within its proximity, and the ceiling electrode attracts the ions with valence opposite in sign to the potential of the ceiling electrode. The remaining ions are emitted within the space of the enclosure and serve to cleanse the air through removal of dust particles, and to further produce air with particularly desirable characteristics.

United States Patent Eichmeier AIR IONIZATION AND CLEANING ARRANGENIENT [72] lnventor: Joseph Eichmeier, Munich, Germany [73] Assignee: Constantin Graf von Bercltheim,

Weinheim/Bergstrasse, Germany [22] Filed: April 15, 1969 [21] App1.No.: 817,613

Related US. Application Data [63] Continuation-impart of Ser. No. 657,283, July 31, 1967, abandoned.

[30] Foreign Application Priority Data Dec. 24, 1966 Germany ..B 90478 [52] US. Cl ..55/l02, 21/74 R, 55/139, 55/146, 55/148, 55/150, 55/155, 55/385,

[51] Int. Cl .303: 3/38 [58] Field of Search ..55/l0l,102, 139,146, 4148, 55/150,155, 385; 21/74 R; 98/1; 128/190;

250/44; 315/111; 317/4, 262 R, 262 AB 143 Nov. 14,1972

2,972,680 2/ 1961 Hicks et al ..250/44 2,983,847 5/ l 961 Spengler ..3 15/1 1 1 3,311,108 3/1967 Cristofv et a1. ..3 1 7/4 X FOREIGN PATENTS OR APPLICATIONS 626,387 4/1963 Belgium.......................55/279 816,463 5/1937 France ..55/l50 337,178 5/1959 Switzerland ..55/1 50 OTHER PUBLICATIONS Martin, T. L., Jr., Production of Unipolar Air with Radium Isotopes," Reprint From Electrical Engineering, January 1954, 6 pages.

Primary Examiner-Dennis E. Talbert, Jr. Attorney-Michael S. Striker ABSTRACT [56] References Cited potential of the ceiling electrode. The remaining ions are emitted within the space of the enclosure and UNITED STATES PATENTS serve to cleanse the air through removal of dust parti- 1 d t furth 0d 'th rt' ul 1 977,336 11/1910 Shaffneretal. ..204/31s 3: :1 z zz zf 2,681,061 6/1954 Modell ..l28/172.1 2,928,941 3/1960 Hickset a1 ..5$/l02X 2,928,942 3/1960 Hicks et a1 .250/44 mhimmnm'ngmu" 2,939,006 5/1960 Oswald ..55/l02X 5?, 7 9 I 4 I 1 A so 7, 3

i x 8% a a 8 Cl 1 I \2 8d 8b 11 26 4 I AIR IONIZA'I'ION AND CLEANING ARRANGEMENT This is a continuation-in-part application of my copending application Ser. No. 657,283, filed July 31, 1967 now abandoned.

BACKGROUND OF THE INVENTION Air conditioning devices have, heretofore, been equipped with two electrodes connected to a high voltage DC source for the purpose of generating an electrostatic field between the electrodes. in a general arrangement, one of the two electrodes is connected to a positive terminal of the source and is located beneath the ceiling of the space to be air conditioned. This electrode is isolated from the ceiling. The other electrode is arranged within the floor of the room, and is connected to the negative terminal of the high voltage source. In this arrangement, it is possible that the ceiling electrode have positive potential applied to it, while the negative terminal of the voltage source is grounded so that the floor of the room itself forms the counter-electrode to the ceiling electrode.

It has also been suggested to arrange one of the electrodes electrically insulated in the floor, and to connect this electrode with the negative terminal of the voltage source. The positive terminal of a source is then grounded so that the walls and ceiling of the room form the counter-electrode to the floor.

All of the devices of the aforementioned type have as their aim to generate a potential difference within the room to be air conditioned so as to simulate the conditions existing in the free air on a clear weather day. These air conditioning devices are particularly applicable to modern concrete buildings and supplement the usual air conditioning features of temperature control, humidity and dust-content control.

By providing an electrode arrangement in conjunction with the conventional conditioning devices, it is possible to eliminate dust much more readily than with a conventional dust-removable device which requires the arrangement of air circulators and separator filters.

A clear weather day in the open atmosphere may be characterized by the following data: relative humidity approximately 50 percent, temperature approximately 20"C., air pressure substantially high, dust contents of the air substantially low, concentration of microions 200 to l,000 per cubic centimeter, concentration of macro-ions several thousand per cubic centimeter, voltage drop or voltage difference 100 to 200 volts per meter, and vertical flow about lO "AIcm. Air conditioners of the conventional type can adjust only specific ones of the preceding factors such as relative humidity, temperature and dust content. By equipping the air conditioning devices with electrode arrangements, furthermore, the voltage difference and the vertical flow can also be adjusted. The electrode arrangement also contributes to dust removal or at least participates therein. The control of the concentration of microions and macro-ions has not, however, been possible heretofore. Due to the high cost of adjusting the air pressure, furthermore, this feature of atmospheric control has also to be dispensed with except in very special cases.

In the application of the conventional electrode arrangements in conjunction with air conditioning devices, it has been found that ion rarification within the space being air conditioned takes place in the course of time due to the tendency of the ions to accumulate at the corresponding electrodes.

Accordingly, it is an object of the present invention to provide an electrode arrangement in conjunction with an air conditioning device for adjusting the concentration of microions and macro-ions, in addition to the adjusted parameters provided by the conventional air conditioners.

It is a further object of the present invention to provide an electrode arrangement for use with air conditioning devices, wherein the concentration of microions and macro-ions can be maintained at a steady level, and a change in voltage difference and vertical flow is avoided over an extended period of time. The preceding objectives are accomplished through the present invention by providing an electrode arrangement suitable for use in an enclosed space, particularly a building or vehicle. In this electrode arrangement, at least one pair of spaced electrodes are connected to opposite terminals of a high voltage DC source so as to generate an electrostatic field between the electrodes and within the space containing them. An electron emitting material, furthermore, is associated with at least one of the two electrodes. The electron emitting material is preferably a radioactive material such as tritium.

Tritium discharges beta particles (electrons) with a maximum energy of 18,000 electron-volts correspond ing to a maximum range of about 7 mm in air at atmospheric pressure. The particles ionize the molecules of the air. As a result of such ionization, positive and negative atmospheric microions become generated in proximity of the radioactive tritium. In accordance with the present invention, the electron discharge material or the supporting member for the radioactive substance may be connected, as desired, with either one of the terminals of the voltage source. When the radioactive substance is to be suspended from the ceiling within the space to be air conditioned, it is desirable that the supporting members for the radioactive substance be of insulating material. The supporting members may be provided with slots or grooves shaped to retain the radioactive substance in the form of metallic strips which are made radioactive through exposure to tritium gas. The radioactive strips are then embedded within the grooves or slots of the supports suspended from the ceiling. In another embodiment of the present invention, the electrode may be mounted within a floor lamp and the radioactive substance is retained within supporting members arranged on top and below the electrode within the floor lamp. Such an arrangement is portable and is particularly advantageous when large distances prevail between the electrode and the ceiling of the space to be air conditioned.

In the air conditioning of the interiors of buildings and vehicles through electrical conditioning arrangements two essential elements are required. One of these is an electrical DC field which corresponds to the conditions prevailing in the free atmosphere. For predetermined values of such a field, clear weather conditions may be simulated and conditions may be established for producing less tiredness and greater mental concentration capability. The other factor or element to be taken into account is the prevalence of a predetermined ion concentration. As a result of the presence of the electrical field, the ions prevailing within the air are attracted to the electrodes establishing the field. With the deficiency of ions established, in this manner, the electroclimatic conditions change in a negative sense. An ion generator is thereby provided through which ions of one valence or sign are predominantly fed into the space to be conditioned. The introduction of ions of one sign or valence has a number of advantages. One of these advantages is that ions of different signs or valences recombine and become thereby ineffective. A second advantage is that ions of one sign or valence have an additional positive effect upon persons, presumably from the viewpoint of the air breathed. The third advantage resides in the condition that ions of a single or one sign attract dust particles which can then be collected at an electrode.

Heretofore, the apparatus for generating the electrostatic field and the arrangement for generating ions where installed fully independent of each other. In accordance with the present invention, the apparatuses for ion generation and for producing the electrical field within the desired space are combined with each other so that the blower used in conjunction with the ion generator, heretofore, and the dust particle collecting electrode may be avoided. in accordance with the present invention, one electrode used to generate the field serves as the collecting electrode, whereas the electrode emitting substance is arranged in the region of this electrode. As a result the ions of a predetermined sign or valence travel directly to this neighboring field electrode. The electrical field as established in the present invention, serves, at the same time, for moving the air ions. An air ion stream or air ion current is generated as a result of the movement of the ions of a predetermined sign or valence to the collecting electrode and through the space being conditioned.

SUMMARY OF THE INVENTION An arrangement for conditioning the air within an enclosure. An electrode is suspended from the ceiling through the use of electrical isolators between the ceiling and the electrode. A second or counter-electrode is arranged on the floor of the enclosure or embedded therein. A high DC voltage supply applies a voltage between the two electrodes and consequently across the height of the room or enclosure being conditioned. Radioactive material for emitting electrons and thereby ionizing the surrounding air is supported in cross members secured to the underside of the ceiling electrode. These cross members are slotted to retain the radioactive substance in the form of strips which were made radioactive through exposure to tritium gas. Upon ionizing the air within the proximity of the radioactive strips near the ceiling the ions having a valence or sign opposite to the potential of the ceiling electrode, become attracted to that electrode. As a result, ions of one sign or valence are emitted into the space or room being conditioned.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The drawing shows a cross sectional schematic view of the space to be conditioned, and shows the relationship of the electrodes generating the electrostatic field and the radioactive material for ionizing the air.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawing, a first metallic electrode 3 is suspended from the ceiling 1 within the confinements of an enclosed space or enclosure 2 inhabitable by human beings. lsolators serve to electrically isolate the electrode 3 from the ceiling, walls and floor of the space 2. The metallic electrode 3 may be constructed in the form of a simple metallic plate, or in the form of a metallized surface upon an insulated carrying or supporting plate. Thus, a member of insulated material may have applied to it, a metallized surface for the purpose of forming the electrode 3. This electrode may also be designed in the form of the structure in which metallic foil is glued on, for example, to an insulating plate or member. Accordingly, the electrode 3 may assume that structure in which it has an electrically conductive surface.

The electrode 3 is suspended from the ceiling through simple isolators 20 in conventional use. it is the purpose of these isolators 20 to electrically insulate or isolate a electrode 3 from the structure or building material which defines the enclosed space 2. The isolators 20 are designed similarly to those used in the field of high voltage and allied electrical design. The construction of such isolators 20 for electrically isolating the electrode 3 from the ceiling l, is well known in the art. Electrical isolation between the electrode 3 and the ceiling l as well as the walls and floor of the space 2, is required because a potential will be applied to the electrode 3 differing from the potential of the surrounding ceiling and walls of the space. in lieu of the isolators 20, the electrode 3 may also be secured or suspended from the ceiling 1 through an intermediate member which is located between the electrode 3 and the ceiling 1, and which is of insulating substance. Thus, a plate made of electrically insulating plastics such as polyvinylchloride may be placed between the ceiling surface and the electrode 3 by securing the plastic plate to the ceiling through a glueing substance or similar adhesive. Such an adhesive may then also be used to secure the elec trode 3 to the underside of this plastic plate. In an alternate method for securing the plastic plate and electrode 3 to the ceiling, screws may be used or fastening the electrode 3 to the plastic plate, so that the screws do not penetrate the entire plate and make contact with the ceiling. Thus, the only requirement to be met in suspending electrode 3 from the ceiling is that it be electrically isolated therefrom.

Support means comprising cross members 8 secured to the lower side of the electrode 3 extend lengthwise across the ceiling l of the space 2. These cross members 8 may be secured to the electrode 3 through adhesive fastening means or fastening devices in the form of screws, for example. The cross members 8 are made of insulating substance which is preferably constituted of foam plastics such as polystyrene or polyurethane. The cross members 8 are shaped to contain a slot 11 extending along the longitudinal axis of the cross member. Within this slot 11, an electron emitting means in form of a radioactive strip 12 is held. The electron emitting means constituted by the strips 12 may comprise tritium or metallic strips impregnated with a radioactive substance, for instance, the metallic strips may be immersed in tritium or circonium gas, so that the pores in the strips absorb the gas and thereby become radiactive. As a result of the insulating properties of the substance constituting the cross members 8, the strip 12 is electrically isolated from the electrode 3. The radioactive strip 12 is held within the slot 11 through adhesive means or fastening devices such as screws. As illustrated in the drawing, the radioactive strip 12 does not fill the entire space of the slot 11.

The cross members 8 are spaced from each other so that a space 9 prevails between the backsurface 8a of one channel and the frontal surface 8b of the neighboring or adjacently located cross member 8. Thus, the frontal surface 8b represents the exterior surface of the arms forming this slot 11, and facing the surface 80 of the neighboring cross member 8. The slot 1 l is substantially a U-shaped slot with the arms 8c and 84 forming the arms of the U configuration.

Arranged parallel with the floor of the space 2, is a second electrode 5. The second electrode 5 may be designed in the form of a mesh consisting of electrically conductors laid crisscross to form the mesh or grid. Thus, the electrode 5 in the form of a grid or screen mesh extends across the floor of the space 2, and may be located, for example, beneath the carpet or similar covering 22. The electrode 5 may also be constructed in the form of a simple metallic plate which is electrically conductive or, a plate of insulating substance covered with metallic foil. Accordingly, any suitable design for the electrode 5 is permissible which has an electrically conductive surface. Depending upon the specific construction used for the building in which space 2 is enclosed, the electrode 5 may be incorporated or derived directly from the structural steel members used in the construction of the floor of the building. Accordingly, should sufficient conductive capacity be available within the steel girders or steel mesh which may be used within the concrete floor, the electrode 5 may be derived from this particular construction.

A potential difference is established between the electrodes 3 and 5, through a high voltage source 7. in such an arrangement, for example, positive potential may be applied to the first electrode 3, whereas negative potential is applied to the second electrode 5. The electrode 5, furthermore, may be grounded. The floor covering 22 laid over the electrode 5 may, in one case, consist of a carpet, or wooden floor covering. At the same time, it is noted that the electrode 5 may be directly embedded in the fon'n of a steel mesh used for reinforced concrete for the formation of the floor of the building.

The radioactive strips 12 residing within the grooves or slots 11, are made radioactive through the adsorbtion of tritium of an activity of 5 mC/m which discharge beta particles or electrons. Since the half-life of tritium is about 12.6 years, the tritium source will have a lifetime of about years, which corresponds to a decrease in activity to one-third of the initial value. The radioactive strips 12 function to ionize the air which prevails within the proximity of the strips. If the high voltage source 7 applies to the electrode 3 a DC voltage in the neighborhood of 500 volts, for example, then air ions with valence opposite in polarity to the potential applied to the electrode 3, will be attracted to the electrode. Thus, the radioactive strips 12 ionize the air so as to generate both positive and negative ions. It, now, the voltage source 7 applies a positive potential of 500 volts to the electrode, the negative air ions will be attracted to the electrode 3, and the positive ions will be released into the space 2. It is quite feasible, on the other hand, to reverse the polarity of the high voltage source 7 so that the negative potential is applied to the electrode 3. Under such circumstances, the positive ions resulting from the radioactivity of the strips 12, will be attracted to the electrode 3, and the negative ions will be released into the space 2.

The cross members 8 which carry and support the radioactive strips 12, are spaced from each other so as to generate the space 9 between adjacent cross members, which assures that the ions opposite in sign or polarity to the potential of the electrode 3, will be immediately attracted to the electrode as soon as they are generated through the radioactive strips 12. Thus, the spacing between the cross members 8 is made suffrciently small so as to confine the ionized air in immediate proximity of the electrode 3. The air ions which are then opposite in valence or polarity with respect to the potential of the electrode 3, will not escape into the space 2 and will, instead, be attracted to the electrode 3 in which case they are effectively removed from the space 2. if, on the other hand, the spacing between cross members 8 is made considerably wide so that the space 9 between cross members is substantially large, then a considerable number of air ions may take the alternate path of entering the space 2 rather than being attracted to the electrode 3. It is the function of the electrode 3 to remove air ions of a predetermined valence or sign which is opposite in polarity or sign to the potential of the electrode 3.

in the case that a particular potential control is desired, the undersides of the cross members 8 may have applied to them a metallic coating or metallic foil. Such a metallic coating 24 is electrically conductive and serves to modify the electrical field within the space 2 and in the proximity of the electrode 3. The metallic coatings or metallic layers 24 which may be in the form of metallized film surfaces of foil glued on the bases of the cross members 8, may be electrically interconnected through conductors 26. These conductors lead to the high voltage source 7, by way of a switch 28. As a result of this arrangement, a potential differing from that applied to the electrode 3, may be applied to the conductive layers 24. Through the use of the switch 28, furthermore, the effect of the conductive layers 24 underneath the cross members 8 may be selectively removed or applied. ln an extreme situation, the cross members 8 may also be made of conductive material, in which case the metallic radioactive strips 12 are at the same voltage potential as the electrode 3.

If the electrode 3, as indicated in the preceding example, has positive potential applied to it, the negative ions generated through the radioactive strips 12 will be essentially prevented from entering the space 2, as a result of being attracted to the electrode 3. In the event that it is desirable to emit negative ions into the space 2, however, it is possible to achieve this situation by simply reversing the terminals of the voltage source 7 so that negative potential is applied to the electrode 3, instead. The positive potential would then be applied to the electrode or be grounded. in such a case the positive ions would be attracted to the electrode 3, and the negative ions would be emitted into the space 2.

Depending upon the height of the room or space 2 and the selected voltage for the source 7, a voltage difference between the ceiling electrode 3 and the floor electrode 5 would be of the order of lOO to 200 volts per meter. This condition corresponds essentially to conditions prevailing in the open air on a clear weather day. As a result of the arrangement in accordance with the present invention, furthermore, the concentration of positive and negative ions will be increased homogeneously within the enclosed space. The combination of the voltage drop difference prevailing between the ceiling and floor of the space and the ionization of the air, results in a generation of a flow of ions between the ceiling and the floor electrode. Accordingly, in lieu of a random movement of natural air ions, a directed flow of air ions takes place in the vertical direction, similar to that experienced in the open all.

The air ions generated by the radioactive strips 12 are primarily microions. These microions have the tendency to deposit on condensation nuclei, dust or smoke particles and to form macro-ions. The macro-ions are also moved by the electrostatic field between the ceiling and floor electrode, with the direction of movement being determined by the polarity of the voltage source 7. As a result of such movement applied to the macroions, they are eliminated from the air of the room and thereby produce through such movement, a purification of the air similar to that prevailing in the open atmosphere. The expression microions is used in relation to charged carriers and consist of a number of molecules, usually 12. In some cases, the microions may contain up to a maximum of 30 molecules. Among these molecules, one or no more than two are ionized neither positive or negative. Thus, within these microions, a maximum of two molecules are ionized. In contrast to the microions, macro-ions are formed when microions adhere to suspended particles within the air.

In an alternate arrangement of the electrode system used in connection with the space 2, the floor electrode 5 is electrically insulated from the building structure, and the ceiling electrode 3 is omitted. lf, now, the floor electrode 5 is connected to the negative potential terminal of the voltage source 7, the ceiling 1 will consist of the positive electrode, provided the ceiling possesses the required structural materials in the form of a conductive mesh or conductive structural steel members embedded within the ceiling. In such an arrangement, the cross members 8 carrying the radioactive strips 12 can be secured directly to the ceiling. The radioactive strips 12 may then be either insulated from the ceiling or electrically connected thereto. In this alternate embodiment, therefore, the electrode arrangement is merely reversed from the situation previously described.

Through the distribution of the radioactive strips 12 across the entire ceiling, a homogeneous ion distribution is realized within the space 2. Thus, through the use of a number of parallel strips evenly distributed across the ceiling of the space, the desired ion distribution is realized. Such homogeneity is realized even when turbulent air movements are initially encountered within the space 2. Furthermore, through the particular design of the notches 11 within the cross members 8 of the present invention, a relatively large surface region is realized in which ionization may take place. This construction of the cross members 8 with their slots or notches 11, therefore, also contributes extensively for homogeneity in ion distribution.

The electrode system as used in the present invention, therefore, serve three major functions through the use of a two-electrode system. These three functions are namely, the establishment of an electrical field within an inhabited space; removal of ions having the undesired valence or sign; and the movement of the ions within the space, without the use of auxiliary driving mechanisms.

lt will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in air conditioning systems, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. An arrangement for conditioning air within an enclosure which is inhabitable by human beings, compris ing electrode means including a first electrode and a second electrode, said electrodes being spaced from each other in one direction in said enclosure; a source of DC voltage operatively constructed and arranged for applying a DC potential to said electrode means, said electrodes being operatively arranged and constructed to establish an electrostatic field therebetween; and ion generating means located adjacent to said first electrode in said electrostatic field created in said enclosure, said ion generating means comprising a plurality of support means spaced from each other in a direction transverse to said one direction, each of said support means being attached to said first electrode, and electron emitting means arranged on said support means and operatively constructed and arranged for emitting electrons into the spaces between said plurality of support means and ionizing the air in said spaces and producing atmospheric ions of positive and negative polarity, said first electrode attracting the ions of one polarity and the ions of other polarity traveling in said one direction through the enclosure toward said second electrode and being attracted thereby.

2. The arrangement for conditioning air within an enclosure as defined in claim 1, wherein said plurality of support means comprise a plurality of members of insulating material each formed at one side thereof with a groove facing the support means adjacent thereto, said electron emitting means being located in the grooves of said plurality of members.

3. The arrangement for conditioning air within an enclosure as defined in claim 1 including means for mechanically securing said electron emitting means to said electrode means.

4. The arrangement for conditioning air within an enclosure as defined in claim 1 wherein said electron emitting means comprises tritium.

S. The arrangement for conditioning air within an enclosure as defined in claim 1 wherein said electron emitting means comprises metallic strips impregnated with radioactive substance.

6. The arrangement for conditioning air within an en- 10 closure as defined in claim 1 wherein said enclosure comprises a room having a ceiling and a floor, said first 

1. An arrangement for conditioning air within an enclosure which is inhabitable by human beings, comprising electrode means including a first electrode and a second electrode, said electrodes being spaced from each other in one direction in said enclosure; a source of DC voltage operatively consTructed and arranged for applying a DC potential to said electrode means, said electrodes being operatively arranged and constructed to establish an electrostatic field therebetween; and ion generating means located adjacent to said first electrode in said electrostatic field created in said enclosure, said ion generating means comprising a plurality of support means spaced from each other in a direction transverse to said one direction, each of said support means being attached to said first electrode, and electron emitting means arranged on said support means and operatively constructed and arranged for emitting electrons into the spaces between said plurality of support means and ionizing the air in said spaces and producing atmospheric ions of positive and negative polarity, said first electrode attracting the ions of one polarity and the ions of other polarity traveling in said one direction through the enclosure toward said second electrode and being attracted thereby.
 2. The arrangement for conditioning air within an enclosure as defined in claim 1, wherein said plurality of support means comprise a plurality of members of insulating material each formed at one side thereof with a groove facing the support means adjacent thereto, said electron emitting means being located in the grooves of said plurality of members.
 3. The arrangement for conditioning air within an enclosure as defined in claim 1 including means for mechanically securing said electron emitting means to said electrode means.
 4. The arrangement for conditioning air within an enclosure as defined in claim 1 wherein said electron emitting means comprises tritium.
 5. The arrangement for conditioning air within an enclosure as defined in claim 1 wherein said electron emitting means comprises metallic strips impregnated with radioactive substance.
 6. The arrangement for conditioning air within an enclosure as defined in claim 1 wherein said enclosure comprises a room having a ceiling and a floor, said first electrode being suspended from said ceiling and in proximity of said electron emitting means, and said second electrode being supported by said floor, said source of DC voltage applying a DC potential between said first electrode and said second electrode.
 7. The arrangement for conditioning air within an enclosure as defined in claim 6 including isolating means between said first electrode and the ceiling, said isolating means isolating electrically said electrode first from the ceiling and floor. 